Tropical. Since the country is elongated from north to south for hundreds of kilometers, the climate varies somewhat among the islands. In the north, the annual variations in temperature are practically invisible (the annual average temperature around 26 C), the seasons vary only by rainfall: winter (June - August) is pretty dry, no more than 200 mm. precipitation, more humid summer - up to 600 mm. In the south the climate is more dry, from May to October, falling to 120-150 mm. precipitation in the month, from December to February, about 240 mm., the rainiest month (March) - 400 mm. The water temperature off the coast of Tongatapu varies from +21 C in June to +29 C in November.